Materials World Network: An International Collaborative Educational and Research Program in the Study of Mixed Glass Former Phenomena in Materials

This Materials World Network (MWN) project examines the universally observed Mixed Glass Former Effect (MGFE) where independent of the mobile cation, independent of the two glass formers used, independent of whether the system is all-oxide, all-sulfide, or even mixed oxy-sulfide, and independent of the over-all mobile cation concentration, the ionic conductivities of Mixed Glass Former (MGF) glasses are always higher than that of the two parent binary glasses at the same level of mobile cation concentration. With the recent and well known problems of liquid polymer electrolytes in millions of lithium batteries, there is a renewed interest in solid electrolytes for lithium batteries. Such MGF glasses make ideal candidates due to their anomalously high ionic conductivities and other advantageous properties brought about by the mixing of the glass formers. However, before wide spread application of these electrolytes can be implemented, a detailed understanding of the MGFE must be developed first. For this reason, the intellectual merit of this project is that an international research team has been assembled to form a Materials World Network of research capability from among three universities in the US and three universities in Europe. Researchers in the US are preparing the glasses and measuring the composition dependence of the conductivity and examining short range structures through vibrational spectroscopy (Martin-Iowa State University). Both short and intermediate range structures of the glasses are being examined using high resolution x-ray diffraction (Petkov-Central Michigan University) and tracer diffusion coefficients are being measured (Dieckmann-Cornell). The European collaborators are providing complimentary neutron diffraction (Brjesson-Chalmers Institute of Technology, Sweden) and nuclear magnetic resonance (Eckert- Westfalische Wilhems-Mnster University, Germany) data to extend the detail of structural studies. European collaborators are also providing theoretical modeling and simulation of both the ionic conductivity and structure of the glasses (Maass- Technical University Ilmenau, Germany) and for theoretical modeling of the ion dynamic processes that are apparently greatly magnified in MGFE glasses (Funke-Mnster U., Germany). The project synergistically combines both structural and dynamical studies of the MGFE in oxide, sulfide, and oxy-sulfide glasses to determine the nature, extent, and role of the favorable structural features of MGFE glasses.

The broader impacts of this project are to use new modalities of international collaboration to provide young researchers new education experiences to broaden and deepen their research abilities, and to expand and develop their professional and international awareness to enhance their global citizenry. This is achieved by providing students with unique extended collaborative research and education experiences in the European collaborators' laboratories, and by having them host European students in the US to create professional linkages and experiences throughout this program. Deep collaborations among other MWN projects in similar countries are developed to leverage learning among the MWNs and speed up the development of best practices for such international collaborations. Collaboration is also established with local 2- and 4- year colleges to draw undergraduates, especially women and minorities, to the program to foster new 4 year graduates and new graduate students. The framework of the MWN is also used to develop new modalities of distance utilization of research equipment through common operating systems and high-speed internet connections, and to develop sustainable collaborations among the partners of the program that foster long term progress on research.

This award is co-funded with the Office of International Science and Engineering.